Following a dramatic meeting in the White House, U.S. military support for Ukraine is perilously uncertain. Sustaining Ukraine in this war, and afterwards, is a responsibility that Europe will have to shoulder sooner rather than later. Washington may now cut support for Ukraine well before any agreement is reached and try to compel Ukraine to accept an unstable ceasefire. This will leave Ukraine in a perpetual state of insecurity, and Europe bracing for a possible renewal of the war. There is a significant risk that following a cessation in large-scale combat operations Russia continues its effort to destabilize Ukraine politically, pressure it economically, and set the conditions for a third war on far more favorable terms for Moscow. To prevent this, the Ukrainian military will need to be sustained in the field and reconstituted, while Russia is effectively deterred.

It is increasingly less likely that the United States will continue extending military or financial assistance, with Washington’s policy objective to shift the burden onto European capitals. Despite President Volodymyr Zelensky’s efforts, the United States has made it clear that it does not intend to offer Ukraine security guarantees or directly contribute to any forces supporting Ukraine after the imposition of a ceasefire. It therefore falls upon Europe to plan for such a force. This is a serious undertaking. Can European powers field such a force without hollowing out Europe’s ability to defend NATO’s borders, all while the United States potentially withdraws forces from the continent?

While the length of front and the size of Russian ground forces may give the impression that the task is infeasible, in our view it is practicable if European nations are willing to pay the cost. With the right force balance, investment, and political framework Europe could generate a credible commitment.

There is nothing fantastical about a European mission in Ukraine. France and the United Kingdom are considering such a proposal and, as recent reporting suggests, have discussed it during President Emmanuel Macron’s recent visit to Washington. Turkey may be open to contributing to such a force as well. Indeed, while Zelensky’s meeting with Trump in Washington was a catastrophe, it may have increased European will to do much more than it might have otherwise. However, the conversation remains ill-informed in terms of requirements, either implying that a token force will be sufficient or inflating the necessary troop levels to a point that renders such a policy impossible. We seek to set a realistic marker for what would be required if Europe were to deploy forces in Ukraine.